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A recent video accidentally leaked by the U.S. Naval Surface Warfare Center (NSWC) Carderock Division reveals a previously unknown hydrofoil ship. The video, which has been accidentally uploaded to Youtube, shows the ship sailing at high speeds on its foils. Shortly after the classified video came to light, it was taken down but twitter user @lfx160219 who managed to upload a gif showing the vessel practically hovering over the water at high speeds.

The NSWC Carderock Division is one of the U.S. Navy’s research and development facilities, with the Carderock Division mainly researching and working on ships. The video shared on Youtube clearly showed a hydrofoil ship, but there are currently no known Navy hydrofoils in operation.

Hydrofoil ships are different than traditional vessels since they have large, foldable foils on the underside of the ship. When the ship reaches a high enough speed, the ship rises from the surface, with the foils being the only contact the ship has with the water. This increases the ship’s speed significantly since drag is reduced, this also creates a much smoother ride.

A little over 30 years ago, the U.S. Navy operated a fleet of hydrofoil ships of the Pegasus class. With the hydrofoils retracted, the ship could sail at a modest speed of 12 knots. However, once the hydrofoils extend, the ship could reach speeds of up to 48 knots.

Each Pegasus was heavily armed with Harpoon anti-ship missiles and a 3 inch gun, as reported by popularmechanics.com, although most of the time the Pegasus ships would patrol the Caribbeans for drug smugglers.

The Pegasus’ life span in the Navy was relatively short, with the ship’s retirement in the 1990’s. With the Pegasus’ retirement also came the Navy’s retirement of hydrofoil ships. The leaked video is the first time we get to see the Navy’s interest in hydrofoils since the 90s.

The video shows us a hydrofoil much smaller than the Pegasus class ships, with a featureless hull and a radar/sensor mast sticking out from the rear.

It is unclear what the Navy has planned for hydrofoils in the upcoming years. It may be possible that the leaked video shows off a hydrofoil prototype that may be in military use in the next few years, and it may also be possible that the ship has already been in military operations right under our noses.